The theme was "Casual Addiction", and I wanted to develop something with a simple score-based mechanic that encouraged exploration and strategy to keep the player hooked on trying to improve his performance.

I'm a big fan of classic competitive puzzlers like Puyo Puyo and wanted to put that kind of complexity and depth into a score-driven experience. The game mechanic - sliding gems together to form squares and rectangles - worked perfectly on a touchscreen.

When I started work on the iPad version my intention was to make full use of the large screen, to do something that wouldn't have been possible on the phone. Multiplayer was a fantastic opportunity to do that.

Having another player to take on makes the gameplay so much more unpredictable. This allowed me to add in more exciting strategic elements, and to extend the gameplay outside the screen and into real-world interaction.

What do you think Greedy Bankers offers gamers that similar titles in the App Store don’t?

I like to think that the multiplayer is unlike any other game on the Store. Two players play simultaneously on a shared iPad, with each player controlling his own side of the game board.

Players can reach across the board and steal each other's gems, with each stolen gem earning a bonus multiplier. Because of this, players are encouraged to steal and cheat, and how they do that is up to them - finger jousting and arm grabbing are all fair game if you want them to be.

Showing the game at the Eurogamer Indie Arcade last weekend was fantastic because I got to watch just how sucked into it opponents got. There was one game that practically turned into a wrestling match. Luckily, no iPads were harmed, and there have been no spilt pints yet. But I want to leave it up to players to decide what's acceptable behaviour.

I also designed the game to provide plenty of emergent strategies, so that there's always something to explore, and different ways to use obstacles and power-ups to your advantage.

That's evident in the multiplayer, as well as in the single-player arcade mode that forms the basis of the iPhone version. Greedy Bankers is all about quick thinking: to maximise your score, you need to be able to change your strategy on the fly.

Did you encounter any issues bringing Greedy Bankers over from the iPhone to the iPad?

I had to redesign some of the artwork to make it look right in a different screen orientation, but porting the original was pretty simple.

The hardest parts were what I brought upon myself - I got much more ambitious thanks to the larger screen. As well as the larger playing field and multiplayer elements, I worked on an AI Story mode where you can run a gauntlet full of computer opponents.

This means that lone players can also enjoy multiplayer battles. Whilst this is the most complex AI I've ever coded, since it needs to solve the puzzles on its own as the game board changes, it was really fun to do. The AI opponent ended up being very good at the game, but balancing the difficulty curve was a big challenge.

I plan to add in the top-level difficulty mode as an unlockable extra in a future update.

Do you have any plans to support either the iPhone or iPad version of Greedy Bankers with future content updates?

Definitely. I want to keep updating them based on player feedback, such as what rules they like to use, and to keep on balancing the Story Mode difficulty.

As well as the extra difficulty levels, I'll be adding in Game Center support soon. Depending on how people respond, I'm considering adding wi-fi and online multiplayer.

With the iPhone version, I hope to work in some of the new features from the iPad version and maybe some extra game modes.

Will you be porting Greedy Bankers to any other mobile platforms?This is something I would love to do, but it would be a lot of work. The game was coded in Objective-C, which means a port to another platform would probably mean a fairly sizeable re-code.

However, I'm definitely not going to rule it out. I guess it's just a case of waiting to see how the iOS versions do.Are you currently working on any other mobile projects?

Right now, I'm putting all my effort into the Greedy Bankers games, but of course there's plenty in the pipeline.

I'll probably put together a few prototypes for the next project and see what players enjoy most, before starting full-time on that project. I also plan to make the next game multi-platform right from the start.

But now that Greedy Bankers is out on iPad, my priority is to get as much out of it as I can in terms of building up the brand, getting feedback from the audience, and gaining experience in running my little one-man studio!

Thanks to Alistair for his time.

You can grab Greedy Bankers for your iPhone right now for 69p / 99c and for your iPad for £1.99 / $2.99.